To extend each frame's time on CS3 it is easier than it looks.
Step 1
Left click the individual keyframe you would like to extend the timing on
Step 2
Right click and a list will show up, click on insert frame and the time of that keyframe will be extended.
Step 3
And you've extended that keyframe's time
*TIPS
1. The shortcut to add a frame is to instead of right clicking, you could press F5 the key command to add a key command
2. If you want to copy more than one keyframe you could select the already copied frame and click on Shift and then right click and click on insert frame.
Step 1
Left click the individual keyframe you would like to extend the timing on
Step 2
Right click and a list will show up, click on insert frame and the time of that keyframe will be extended.
Step 3
And you've extended that keyframe's time
*TIPS
1. The shortcut to add a frame is to instead of right clicking, you could press F5 the key command to add a key command
2. If you want to copy more than one keyframe you could select the already copied frame and click on Shift and then right click and click on insert frame.